collimate

Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

transitive v. To make parallel; line up.

transitive v. To adjust the line of sight of (an optical device).

from Wiktionary, Creative Commons Attribution/Share-Alike License

v. To focus into a narrow beam or column.

from the GNU version of the Collaborative International Dictionary of English

transitive v. To render parallel to a certain line or direction; to bring into the same line, as the axes of telescopes, etc.; to render parallel, as rays of light.

from The Century Dictionary and Cyclopedia

To bring into the same line, as the axes of two lenses or the telescope of an optical instrument; also, to make parallel, as the rays of light passing through a lens.

To render the line passing through the optical center of the object-glass of a telescope and the middle wire of its reticule strictly perpendicular (or sometimes parallel) to the axis on which the telescope turns: usually by the aid of a collimator, or of star-observations in reversed positions of the instrument.

In 2005 they used high-power ‘Luxeon’ LEDs, i.e. non-coherent sources, combined with a large Fresnel lens to collimate the non-directional light emitted, and managed two-way audio communications over a distance of 160 km (100 miles!) between mountaintops in Tasmania.

Using a light pipe [such as fiber optic] won't help to collimate your beam, total internal reflection means that as the angle of incidence = = the angle of reflection, the light entering the pipe at random angles will exit just as randomly.

There are two nouns morion kind of helmet, does not concern us here (it is probably from Spanish smoky quartz, has an interesting etymology: it is from a Latin word here about collimate, from an erroneous reading of Latin collineare; I wonder if there is a list somewhere of words with similar histories?